In a semiconductor manufacturing process, a plasma process is widely performed to form or etch a thin film, or the like. To obtain a highly functional high-performance semiconductor, it is desirable to perform a uniform plasma process on a processing target surface of a processing target object.
In a plasma process, plasma of a processing gas is generated. The plasma contains active species such as ions and radicals. The plasma process is performed by reacting the processing target surface of the processing target object with the plasma containing the ions and the radicals.
Recently, for the semiconductor manufacturing process, there has been proposed a plasma processing apparatus in which a grid electrode provided with a multiple number of through holes are disposed within a processing vessel for performing therein the plasma process on the processing target object, and the inside of the processing vessel is divided into two spaces by the grid electrode.
In this plasma processing apparatus, the processing target object is placed on a mounting table which is provided within a processing space under the grid electrode, and a processing gas for use in the plasma process is supplied into a plasma generation space above the grid electrode. Further, in this plasma processing apparatus, a plasma of the processing gas supplied into the plasma generation space is generated by supplying a high frequency power to the plasma generation space. Furthermore, in this plasma processing apparatus, the processing gas and the radicals in the plasma generated in the plasma generation space are attracted into the processing space from the plasma generation space via the grid electrode by depressurizing the processing space. Further, in this plasma processing apparatus, a plasma of the processing gas introduced into the processing space is generated by supplying a high frequency bias power to the mounting table, and the ions in the generated plasma are attracted into the processing target object placed on the mounting table. Through these operations, a uniform plasma process can be performed on the processing target object while controlling the density of the radicals in the plasma.                Patent Document 1: Japanese Patent Laid-open Publication No. H11-067737        Patent Document 2: Japanese Patent Laid-open Publication (Translation of PCT Application) No. H07-500459        